The titanium silicate mineral penkvilksite is available only in trace quantities and therefore its chemical properties are unknown and difficult to analyze. The chemical composition of ETS-14 is similar to that of penkvilksite but the morphology differs substantially from that of the structurally related mineral.
The following references relate to the mineral penkvilksite:
A. N. Merkov, I. V. Bussen, E. A. Gofko, E. A. Kulchitskaya, Yu P. Menshikov, and A. P. Nedorezova, Zap. Vses. Mineralog. 102. 54 (1973).
I. V. Bussen, Yu. P. Menshikov, A. N. Merkov, A. P. Nedorezova, Ye. I. Uspenskaya, and A. P. Khomyakov, (1975) Penkvilksite, a new titanium-sodium hydrosilicate. Doklady Earth Science Section, 217, 126-129 (translated from Doklady Akademii Nauk SSSR, 217, 1161-1164) (1974).
M. Fleischer, New Mineral Names, American Mineralogist, 60, pp 340-341 (1975).
P. A. Sandomirskii and N. V. Belov, The OD Structure of Zorite, Soviet Physical Crystallography, 24 (6) (1975).
S. Merlino, M. Pasero, G. Artioli, A. P. Khomyakov, Penkvilksite, a new kind of silicate structyre: OD character, X-ray single-crystal (1M), and powder Rietveld (20) refinements of two MDO polytypes, American Mineralogist, 79,pp 1185-1193 (1994).